This invention relates generally to tamper evident recloseable bags of the type typically fabricated from plastic film and having two opposing bag walls, and is particularly concerned with a novel hooded closure structure for said bags.
Several methods of construction for tamper evident bags are known in the art. These methods include sealed bag walls above the fastener profile assembly and the use of fastener profile assemblies or other closeable arrangements which are of a permanent type. These methods have several disadvantages which the present invention solves. A common problem associated with tamper evident bags having a sealed top edge above a fastener profile assembly is the difficult opening process. Because the upper portion of bag walls are normally constructed for durability and rigidity to make opening of the fastener assembly easier, this portion has a heavy wall thickness. The heavy wall thickness is not conductive to tearing, for access to the fastener assembly. Even where the walls are perforated as in U.S. Pat. Nos. 3,827,472 and 3,266,787, tearing of the upper portion is still laborsome because the walls must still be thick enough to have fastener profiles sealed thereon.
Other methods have been tried in connection with a sealed top edge such as having a tear strip behind or extruded in the upper portion of a bag wall. Opening is achieved by pulling the tear strip from one end of the bag to the other thereby ripping the tear strip through the bag wall. The same problem of having durable rigid upper wall portions still exists, which makes pulling the tear strip difficult. Even where the area in front of the tear strip is of a lighter construction, as in U.S. Pat. No. 3,619,395, there is a problem of having a jagged top edge once the tear strip is ripped through the bag wall. In addition, bags having sealed top ends must be filled through the bottoms, which are sometimes more difficult to handle.